/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/

new Promise( ( resolve, reject ) => {
  resolve()
} ).then( () => {
  let a = 'hello'
  return a
} ).then( ( res ) => {
  let b = 'lagou'
  return res + b
} ).then( ( res ) => {
  let c = 'I ♥ U'
  return console.log( res + c );
} )

Promise.resolve( 'hello' ).then( v => v + 'lagou' ).then( v => v + 'I ♥ U').then(r=>console.log(r))

